Role of Mediterranean diet in the prevention of cognitive decline: Biological mechanisms behind longevity promotion

Cognitive decline and dementia represent escalating global health challenges with limited therapeutic options, highlighting the need for effective preventive strategies. Among lifestyle interventions, diet has emerged as a key modifiable factor influencing brain health. This review aimed to provide an overview of the role of the Mediterranean diet in the preservation of cognitive function and neurodegenerative diseases. Core constituents of the Mediterranean diet provide a wide array of neuroprotective nutrients, including omega-3 fatty acids, monounsaturated fats, fiber, B vitamins, and bioactive molecules, including oligopeptides and (poly)phenols. These compounds collectively exert antioxidant and anti-inflammatory effects, enhance synaptic plasticity via pathways such as PI3K/Akt and BDNF signaling, modulate amyloid-β and tau pathology through SIRT1 and BACE1 regulation, and improve cerebrovascular function. Emerging evidence also implicates gut microbiota in the relation between diet and brain health. Observational and interventional studies consistently associate greater adherence to the Mediterranean diet with slower cognitive decline, reduced incidence of mild cognitive impairment, and lower risk of Alzheimer's disease. The Mediterranean diet offers a biologically plausible and evidence-supported strategy for cognitive preservation. Understanding the specific contributions of individual dietary components and their mechanisms may contribute to targeted nutritional interventions to mitigate the burden of cognitive decline in aging populations.